One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,6)(5,8)(9,10)(11,21)(12,26)(13,17)(14,31)(15,20)(16,23)(18,28)(19,27)(22,33)(24,36)(25,38)(29,37)(30,35)(32,39)(34,40) involution — undirected(1,3,5,4)(2,6,8,7)(11,22)(12,13)(14,27)(16,32)(17,26)(18,35)(19,31)(21,33)(23,39)(24,40)(25,29)(28,30)(34,36)(37,38)(1,3,5,4)(2,7,8,6)(9,11,13,29,14,24,28,40,15,25,30,22,27,39,12,23)(10,16,26,32,19,33,35,38,20,34,18,36,31,37,17,21)(1,4,5,3)(2,7,8,6)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.